When a hard disk drive is abandoned or reused, data recorded on a hard disk as a recording medium in the hard disk drive are commonly erased in view of confidential nature.
Such erase of recorded data in a hard disk drive is conventionally done by repeatedly writing predetermined data such as “00” over data on the hard disk. However, the erasing process by the data overwriting has a problem of heavy workloads and time-consuming. For example, it takes more than 12 hours to erase data on a hard disk of 20 gigabytes of storage capacity.
On the other hand, as an eraser for erasing data on floppy disks and tapes, which are also recording media, a toroidal coil formed by a conductive wire wound around an outer periphery of a ring-shaped core, arranged in a casing of an eraser body and connected to an AC power is known. The eraser arranges a floppy disk or a tape at an outer face of the eraser body and applies an alternating current to the coil from the AC power so as to generate an alternating magnetic field, whereby erasing data recorded on the floppy disk or the tape.
However, in the case of erasing data in a hard disk drive by using the eraser, since a hard disk inside the hard disk drive is accommodated within a casing made of metal such as iron and aluminum, the magnetic force does not reach the hard disk inside the hard disk drive, failing to erase data recorded on the hard disk only with the hard disk drive arranged at an outer face of the eraser and with a magnetic field generated by the eraser. To generate a stronger magnetic field, there is a problem to make a coil heavier, resulting in increasing a weight of the entire eraser.
It is therefore an object of the present invention made in view of the problems and drawbacks described above to provide an advanced recorded data eraser for a hard disk drive that erases data recorded on a hard disk readily and with certainty.